What is the difference between PoE, PoE+ and PoE++ switches?

- Nov 25, 2020-

What is PoE? What is a PoE switch?

PoE (also referred to as the IEEE 802.3af standard) is a new standard based on Power over Ethernet system promulgated by the IEEE 802.3 working group in 2003. The standard stipulates that the power receiving device (PD), such as a VoIP phone, only needs to use two twisted pairs of the same network cable to be powered during the power receiving process, and its PoE power consumption can reach up to 12.95W. If you want to know more about PoE, you can click to view "About PoE power supply, there is everything you want to know"

PoE switch, also called PoE power supply switch, is an application based on PoE technology. It is a switch that can provide power and data transmission to the power receiving terminal at the same time through a network cable, and belongs to a power supply terminal equipment (PSE). If you want to know more about PoE switches and their working principles, you can click [Questions and Answers] What is a PoE switch? Why do you need a PoE switch? Generally speaking, a PoE switch compliant with the 802.3af standard can support a maximum power supply of 15.4W per port and a power supply voltage of 44V-57V. The input voltage of the PoE device connected to this PoE switch is 37V-57V.


What is PoE+? What is a PoE+ switch?

PoE+ (also referred to as the IEEE 802.3af standard), as an upgrade to PoE technology, is a PoE technical standard released in 2009. With the widespread application of PoE technology, some power-receiving devices such as wireless APs require much more power than 12.95W. In order to solve this problem, the IEEE 802.3 working group released PoE+ technology designed to provide higher power to devices.

The PoE+ switch is similar to the PoE switch we mentioned above, and it also supplies power to the PoE terminal device through a network cable. The difference is that the maximum power supply for each port of the PoE+ switch is 30W, and the power supply voltage is 50V-57V. The maximum power supply received by the power receiving device can be increased to 25.5W, and the voltage can be increased to 42.5V-57V.


What is PoE++? What is a PoE++ switch?

With the continuous development of the PoE application market, the IEEE 802.3 standard family once again ushered in a new member in 2018: the IEEE 802.3bt standard. At this point, PoE++ technology has also emerged. Under the IEEE 802.3bt standard, PoE++ technology has two branch types. One PoE++ technology called Type3 can be powered by two or four twisted pairs of the same network cable, and can provide up to 51W of input power for the power receiving device. The other is the Type4PoE++ technology, which needs to supply power to the PoE terminal device through all pairs of the network cable, and the input power can reach 71W. In addition, there is a PoE technology based on the IEEE 802.3bt standard called UPOE (universal power over Ethernet). This technology is proprietary to Cisco, and the working mode is similar to Type3PoE technology (PoE + +), and the input power that can be provided to the receiving end device is 51W. Therefore, some people in the industry will also regard UPOE as PoE++.

As an upgrade to PoE switches and PoE+ switches, PoE++ switches can provide up to 60W of power per port for Type3PoE++ switches and 100W for Type4. Different switches have different output power, input power, and supported network cable types.

How to buy PoE switches compared to PoE+ and PoE++ switches?

From the previous introduction, we can see that PoE switches are different in power supply size and working mode compared to PoE+ and PoE++ switches. These differences will also have a corresponding impact on their respective applications.

A PoE switch based on the 802.3af standard usually has a power supply of no more than 15.4W per port, and can be connected to VoIP phones, sensors, measuring instruments, wireless APs with two pairs of antennas, static surveillance cameras and other terminal devices. The PoE+ switch can support higher-performance movable zoom cameras, wireless APs with six pairs of antennas, IP phones, and so on.

Type3PoE++ switches with higher power supply capabilities can support the connection of video conferencing system accessories and building management equipment, etc. Type4PoE switches can support devices with higher power consumption requirements such as laptops and TVs.


Conclusion

As people's requirements for equipment power supply capabilities have increased, power over Ethernet technology has also been continuously improved and developed. Driven by this trend, switches based on PoE technology have also evolved from the initial PoE switches to the recent PoE++ switches.